Date: Thu, 5 Nov 2015 21:22:23 +0000 (UTC) From: John Baldwin <jhb@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-9@freebsd.org Subject: svn commit: r290413 - in stable: 10/gnu/usr.bin/gdb/kgdb 9/gnu/usr.bin/gdb/kgdb Message-ID: <201511052122.tA5LMN9s036092@repo.freebsd.org>
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Author: jhb Date: Thu Nov 5 21:22:23 2015 New Revision: 290413 URL: https://svnweb.freebsd.org/changeset/base/290413 Log: MFC 288371: When XSAVE support was added on amd64, the FPU save area was moved out of 'struct pcb' and into a variable-sized region after the structure. The kgdb code currently only reads the pcb. It does not read in the FPU save area but instead passes stack garbage as the FPU's saved context. Fixing this would mean determining the proper size of the area and fetching it. However, this state is not saved for running CPUs in stoppcbs[], so the callback would also have to know to ignore those pcbs. Instead, just remove the call since it is of limited usefulness. It results in kgdb reporting the state of the FPU/SIMD registers in userland, not their current values in the kernel. In particular, it does not report the correct state for any code in the kernel which does use the FPU and would report incorrect values in that case. Modified: stable/9/gnu/usr.bin/gdb/kgdb/trgt_amd64.c Directory Properties: stable/9/gnu/usr.bin/gdb/kgdb/ (props changed) Changes in other areas also in this revision: Modified: stable/10/gnu/usr.bin/gdb/kgdb/trgt_amd64.c Directory Properties: stable/10/ (props changed) Modified: stable/9/gnu/usr.bin/gdb/kgdb/trgt_amd64.c ============================================================================== --- stable/9/gnu/usr.bin/gdb/kgdb/trgt_amd64.c Thu Nov 5 20:24:56 2015 (r290412) +++ stable/9/gnu/usr.bin/gdb/kgdb/trgt_amd64.c Thu Nov 5 21:22:23 2015 (r290413) @@ -66,7 +66,6 @@ kgdb_trgt_fetch_registers(int regno __un supply_register(AMD64_R8_REGNUM + 6, (char *)&pcb.pcb_r14); supply_register(AMD64_R15_REGNUM, (char *)&pcb.pcb_r15); supply_register(AMD64_RIP_REGNUM, (char *)&pcb.pcb_rip); - amd64_supply_fxsave(current_regcache, -1, (struct fpusave *)(&pcb + 1)); } void
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